Hulu said Wednesday that subscribers who paid $10 a month during the preview period will receive credit for the difference.
Hulu's service offers back seasons of NBC, Fox and ABC and other TV shows, such as "30 Rock" and "Glee."
The site is jointly owned by General Electric Co.'s NBC Universal, Fox owner News Corp., ABC owner The Walt Disney Co. and Providence Equity Partners.
The free portion of the site has less content and remains available.